Xerostomia, commonly known as dry mouth syndrome, is a condition in which there is a dryness of the mouth due to the lack of normal salivary secretion. As discussed by W. S. Pray, Pharmacists, May 1994, pp. 16-24, many oral functions may be compromised due to the lack of saliva. There may be difficulty in speaking and swallowing as well as a loss of taste. Chewing may also become difficult which may affect the nutritional condition of the patient. Drying of the mucosa may also result in mucositis, inflammation, fissuring and ulceration. Saliva is also known to provide buffering and cleansing actions, so patients suffering from xerostomia often experience decalcification of tooth surfaces as well as periodontal disease.
There are many causes of xerostomia. Salivary ducts can be obstructed or become inflamed by viral or bacterial infections. Radiation therapy to the head and neck regions can result in injury to the salivary glands. Xerostomia is often a secondary condition to other medical aliments, such as Sjogren's Syndrome, hypertension, cystic fibrosis and lupus. Xerostomia may also be induced by emotional conditions, such as fear, excitement, anxiety and other psychological problems, such as depression. Pray, supra, also reports that as many as 400 medications have been implicated in causing xerostomia. Such medications include antihypertensives, anorectics, anticonvulsants, antiparkinson agents, brochodialators, antipsychotics, antidepressants and tranquilizers.
Xerostomia is also often associated with the elderly. However, aging by itself does not appear to be a sole cause for decreased salivary flow. Rather, increased medication usage by the elderly as well as age-related medical conditions, such as Sjogren's Syndrome, hypertension, and Type II diabetes mellitus, contribute to the relationship between xerostomia and age. See Pray, supra, page 20.
Various treatments have been proposed for xerostomia. A common approach is to promote salivary flow through the use of gustatory or masticatory stimulation by chewing gum or paraffin wax. Other methods include sucking oral lozenges or hard candy.
Non-prescription saliva substitutes are also available for individuals suffering from xerostomia. Pray, supra, reports that these substitutes are more effective than plain water since they attempt to closely mimic saliva by including glycoproteins. These formulations typically contain carboxymethyl cellulose and/or mucins for lubrication and viscosity, electrolytes for buffering and remineralization, sweeteners, flavoring agents and preservatives. Salivart.RTM., a saliva substitute marked by Gerbauer Company, is an example of a commercially available product.
U.S. Pat. No. 5,156,845 to M. G. Grodberg discusses a dry mouth lozenge for stimulating the flow of saliva. The lozenge includes a base, a sugarless sweetener, and an acidulent, such as betaine hydrochloride, and fluoride for inhibiting the erosion of tooth enamel. A sugarless chewing gum may be used as the base material.
F. W. Parnell in U.S. Pat. No. 4,938,963 describes a technique for treating xerostomia by administering a sweetened composition of Yerba Santa extract to the affected individual. The composition may be formulated as an aqueous solution, a gum or in a lozenge form. The composition may also include an agent to stimulate salivary gland secretion, such as citric acid, ascorbic acid or combinations thereof.
U.S. Pat. No. 5,409,691 to D. E. Swain proposes a saliva substitute for treating xerostomia which contains a topical solution of aluminum acetate, glycerin and a flavoring agent. This solution may further contain lemon extract or other source of citric acid for the purpose of stimulating the salivary gland secretion.
While a variety of products have been proposed for treating the conditions of xerostomia, none have achieved wide spread acceptance in the marketplace. Therefore, a need exists for a product that can be marketed without prescription for the treatment of dry mouth syndrome and that is in a lozenge form so as to avoid handling liquids, such as the commercially available saliva substitutes.